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N men Aua.29. 19.13. I I 1,195,223. Patented Aug. 22, 1916.

'2 SHEETS-SHEET 1.

H. C. HERR. MACHINE FOR EXPANDING SHEETIMETAL. APPLICATION FILED AUG.29. 191a.

Patented Aug. 22, 1916.

W219i asses Z 7672 za/ en-r C jie. U

7 sheet particularly along the line of to a construction adapted for the I tial expansion of' a sheet metal blank as .sheets which is passed therethrough,

' lllil td' lhh l htd PATEN HENRY C. HERB,

VANIA, A C'ORPORATIQN OF PITTSBURGH, PEhINSYLVANIA, ASSIGNOR, BY MESN'E ASSIGN- MEETS, TO SOUTH SIDE TRUST COMPANY,

OF P117351 N SYLVAIN'IA.

m mm

Specification of Letters Patent.

Patented An Application filed August 29, 19 13. Serial No. 787,389.

To all whom it may concern.-

Be it known that 1,, HENRY G. HERB, a citizen of the United States of America, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Mm chines for Expanding Sheet Metal, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to machines for ex panding sheet metal and more particularly dillrenhereinafter set forth.

In the drawings: Figure l is a plan view of the machine. Fig. 2 is a longitudinal section therethrough. Fig. is a cross section. l i 4 is an enlarged section of a portion oi Fig. 3; and Fig. 5 's' a diagram, showingthe path of travel of the blankcarrying chains.

My improved machine is particularly designed for use in expanding stranded metal which are provided with unslitted margins. Such sheets eannotlbe expanded merely by drawing the opposite margins of the sheet apart, for the reason that this would result in a longitudinal contractionof the expanded, stranded portion and the consequent buckling of the unexpanded margins. The longitudinal contraction could be avoided by the elongation of the strands by the drawing process, but this would be insuiiicient, as it would result in weakening the division between the stranded and unstranded portions thereof. I

y improved machine is one designed to differentially expand the stranded product, and further to differentially elongate the strands so as to compensate for their angular movement and to prevent longitudinal contraction.

The expanding machine the slitting machine, in which the sheet is suitably stranded. -As shown, the slitting machine is adjacent to the expanding niaohine and the stranded product is delivered directly to the latter.

The expanding machine comprises a suitable frame A, upon which is mounted a series of rolls B B B etc, arranged in tion:E and F are may be either separate from or forming a continuation of strands from th guides E and F site sides of the pairs above and below the plane of the sheet. There is also arranged upon opposite sides of the frame traveling chains 0, which extend in divergent paths are provided with edge grippers l) for engaging the margin's of the sheet. These chains with their grippers are so guided that during a portion of their forward movement they are arranged parallel to the edges of the unexpended sheet, the grippers being engaged with the sheet this time. The chains and their grippers are then guided through divergent paths and continue in this direction until the expansion is completed, after which they again pass into parallel orbits, the grippers being disengaged from the sheet during this portion of itsmoveinent.

The expansion of the stranded sheet is effected by the drawing apart of its opposite margins by the grippers and chains. This expanding effect is not, however, CGI1- tinuou's in all portions of the sheet at the same time but alternates between diti'ercnt portions. Furthermore, the elongation of the strands, which is necessary to the expansion of the sheet, avoiding longitudinal contraction, occurs during the interval in which said portions are not laterallyexpended, and. is eilected by the successive action of the rolls B B etc. This alternate expansion of different portions of the sheet is efi'ected by the following construceomplelnentary. tongue and gro ve guides arran ed respectively below and above the plane hi the sheet and of strands and to prevent lateral movement thereof. This engagement of the guides with the strands is possible by reason of the fact that during the slitting or stranding of the sheet, alternate strands are de flected' into different planes, as shown in Fig. 4. Thus when the stranded sheet is delivered to the expanding machine, the guides E and F will register with a certain line of strands, and, alter engagement therewith, will prevent lateral movement of said plane of the guides. The are arranged upon oppomachine and run parallel to the direction of the divergent portions of the chain C, but instead'of being continuous these guides are interrupted opposite each of the pairs of rolls B B L etc. Thus when guides is capable of the sheet is in engagement with. the guides only the stranded portion between said lateral expansion, as the portions between the guides and the chains move in a path parallel to the latter. As soon, however, as the guides terminate, the chains continuing in the same divergent. paths will ex'ertga tension on the entire sheet, which will expand the portions outside of the guides well as the central portion. During this interval the rolls will engage the central portion of the sheet and by their drawing action will elongate the strands thereof, so as to com pensate for the longitudinal contracting effect produced by the lateral expansion. The sheet will-then again engage with another section of the-guides, which will confine the expansion to the central portion, and, in this manner the sheet is alternately engaged with the guides and by the rolls until completely expanded.

Inasmuch as the sections occupied by-the guides are of greater length than -the por tions in which the rolls are located, the

maximum expansion efiect is produced in the central portion of the sheet or that portion between the guides, while the outer poring effect on the strands is atthe center and from that point is progressively diminished toward the opposite edges. A further effect of this construction 1s that the central portion of the sheet is effectively held from lateral movement during the interval in Which the guides are not in engagement, while the portion from the center toward the margins of the sheet are clamped to'a lesser degree by the rolls, permitting of the ditlerentialexpansion as previously described.

In more specific construction, the machine comprises guides G for the chains and grippers, which are "moved to form channelsfor rolls H, l. and .l. Two of these rolls serve to guide the chain through a path corresponding to the channel, while the third'roll is attached to the movable jaw of the'gripper, and actuates the samefor engagement and disengagement from the roll;

This jaw is preferably provided with a pin K, which pierces the sheet metal in the marginal portions of the blank and engages a recess L in the lower ]:1.W member. The

V movement of the aw is controlled my the shape of the groove or channel, which is suitably cammcd at certain points.

'lha-guides E and ll are secured, the one to the bed beneath the work and the other tween the guides G. The degree of expan- E and F are cut away at it to re sion may be altered by adjustment of the anblank is delivered from the slitting machine on to the frame A, where it is engaged, first,

by the grippers D up'on that portion 0' of the chain (l which is traveling parallel to the edge of the blank. The blank then passes into engagement with the guides E and F, which initiate the expanding opera t'ion, and it then passes alternately to' the rolls-B and succeeding sections of the guides until the expansion is completed. At the end the fully-expanded blank passes between the parallel portions C of the'orbits of the chain where it is subjected to the action of crowned compression rolls Q. These rolls only cover the expanded portion of the sheet and their function is to harmonize the dif-' ferential thickness, elongation and lateral expansion of the sheet, so that when it is disengaged from the chams its sides will be parallel and the stresses due to the expanding-operation relieved, permitting the sheet to lie flat. The grippers I) are then di'sen gaged from the edges of the sheet, and a set of rolls Q which extend completely across dition.

As before stated, the rolls B B, etc'., are

slightly crowned, so as to produce the greatest pressure at the center of the sheet and the portions which extend beyond the guides lieve pres sure on that portion of the blank.

I claim 2- l 1.. A machine for expanding sheet metal,

comprising constantly-operating means for laterally expanding a stranded sheet, and

coacting means for confining the expansion to different portions of the sheet.

2. A machine for expanding sheet metal, comprising means for constantly drawing. apart opposite edges of a stranded sheet, and coacting means for distributing the expansion differentially throughout the sheet.

3. A machine for expanding sheet metal, comprising means for constantly drawing apart opposite edges of-a stranded sheet, and 'coacting means for distributing the expansion successively between different portions of said stranded sheet.

4. A machine for expanding sheet metal,

comprising means for constantly drawing apart opposite edges of a stranded sheet, coacting means for successively limiting the expansion to a central portion of said sheet, and means for successively rolling said censaid grippers of the comprismg means for ter portion to elongate the strands thereof and to distribute the lateral expansion to the outer portions of said sheetf 5. A machine for expanding sheet metal, comprising means for constantly drawing apart opposite edges of the stranded'sheet,

interrupted guides engaging a line of. limit the expansion strands in said sheet to on one side thereof, and means intermediate said guides for elongating the strands of the expanded portion. i V

6 A machine for expanding sheet metal, comprising means engaging opposite edges of a stranded sheet for advancing the same in divergent planes and coacting guides arranged above and below said sheet for engaging a deflected line of strands and for guiding the sheet thereby during its advancement. I

7. A machine for expanding. sheet metal, comprising grippers for engaging opposite edges of a stranded sheet, means for causing to travel in divergent planes, guides for engaging separate lines of deflected strands in said sheet to direct the same during advancement and to confine the expansion to one side of'said guides, and means intermediate said guides for engaging the expanded portion" and elongating the strands thereof.

8. A machine for expanding sheet metal,

comprising a pair of endless traveling chains, grippers secured to said chains and adapted to engage opposite edge portions of a'stranded blank, and means for guiding said chains parallel 'to the direction of travel olank during the periods when the blank is being engaged and disengaged, and

through divergent paths during the period of engagement.

9. A machine for comprising a pair of endless chains, grippers mounted on said chains, guides forsaid chains directing the same through parallel paths at opposite ends and through divergent paths intermediate said ends, and cams coiiperating with said and disengage the same with the opposite edges of a stranded sheet and respectively in the parallel portions of their travel at opposite ends.

'10. A machine for expanding sheet metal,

' gripping opposite edges of a stranded sheet and for advancing the same in divergent planes, interrupted guides engaging lines of deflected strands and extending parallel to the edges of said expanding sheet metal,-

grippers to engage,

sheet, whereby the expansion is limited to I the portion intermediate said guides, and means'operatin'g in the spaces between said interrupted guides for elongating the strands of the expanded portion, While permittin'g the expansion of the portion previously held'from expansion by said guides.

11. machine for expanding sheet metal, comprising means for differentially expanding a slitted sheet, and means for differentially elongating the strands of said sheet to compensate for said expansion.

12. A machine for expanding sheet metal, comprising means for difierentially expanding the slitted portion of a sheet having an unslitted margin, and means for differentially elongating thestrands of the sheet to compensate for said expansion without longitudinal contraction.

13. A machine for expanding sheet comprising means for difi'erentially expanding a. slitted sheet, and crowned compression rolls ior differentially thinning and elongating the strands of said sheet to compensate for said difierential expansion.

14. A machine for expending sheet metal, comprising a series of crowned rolls for advancing and differentially elongating the strands of a slitted sheet, cotiperating mean for diiierentially, laterally expanding said sheet in proportion to the diiierential elongation of the strands thereof, and crowning rolls engaging the expanded portion of said sheet at the completion of the expanding operation, operating to harmonize the linerential thickness and elongation to deliver a iiat sheet with parallel edges.

15, in a machine for expanding sheet metal, the combination with means for differenti'ally expanding a stranded sheet, of V crowning rolls engaging said sheet at the completion of the expansion thereof, oper ating to hainionize the thickness of the sheet with the differential expansion thereof.

16. In a machine for expanding sheet metal, means for drawing apart opposite edges 01'. the stranded sheet, means for confining the expansion of the sheet to one side of said means, and means for adjusting said means for confining the expansion to alter the degree of expansion of said sheet.

In testimony whereof I affix my signature in presence of two Witnesses.

HENRY C. HERE. Witnesses I 'Gno. N. Monro, .712, C. C. Morrison. 

